Hi Mattohm,
I'm not sure I fully understand what you're trying to accomplish. You are trying to have specific data sets within your custom tables and relate them to a specific customer, right? So you would have in your table for example: Sample Customer, Sample Equipment 1, Sample Equipment 2.
Try taking a look at this forum post.
If that doesn't help for what you're trying to do, post back here with some more details and we'll see what we can do.
Hope this helps.
- Justin